### Help in solving algebra problems

I am trying to help my grandson with is home work and I am not much help to him. "Can you help me with solving these problems?" Perform the following operation with fractions: 1. 7 1 -- +-- = 9 3 2. 3 1 -- - -- = 4 6 3. 7 6 -- *-- = 4 11 4 1 1 -- -:- -- =